Techno-Economic Evaluation of Biological and Fluidised-Bed Based Methanation Process Chains for Grid-Ready Biomethane Production

Abstract

Three different power-to-methane process chains with grid injection in two scales (1 MWel and 6 MWel) were analysed regarding their investment and operation cost. The process chains were based on biological or catalytic bubbling fluidised bed methanation in combination with proton exchange membrane or solid oxide electrolyser cells. A bottom-up techno-economic analysis showed a cost benefit of around 17–19% lower biomethane production cost for the bubbling fluidised bed technology as less than a third of the reactor volumes is required for catalytic methanation. This cost benefit is only given in combination with PEM electrolysis, as the high-temperature electrolyser stacks currently result in high investment cost. Based on electricity cost of 5 €-ct/kWhel and a plant size of 6 MWel, biomethane production cost of 13.95 €-ct./kWh for catalytic and 17.30 €-ct/kWh for biological methanation could be obtained, both including PEM electrolysis. A significant efficiency increase by integrating the heat of catalytic methanation reaction with the high-temperature electrolysis can be achieved; however investment cost have to decrease below 1000 €/kWel to obtain economically feasible production cost of biomethane. Under current economic and technological circumstances, CO2 methanation using the bubbling fluidised bed technology is the most cost effective.

Low‐carbon economic optimization method for integrated energy systems based on life cycle assessment and carbon capture utilization technologies

“…Postcombustion flue gas shunt carbon capture for high carbon emission units in IESs to avoid CO 2 entering the atmosphere and reduce CO 2 emissions. By capturing CO 2 emissions by converting them into methane, this method contributes to achieving carbon neutrality 24 . The working principles and process flow of the CCU technology are illustrated in Figure 2.…”

“…By capturing CO 2 emissions by converting them into methane, this method contributes to achieving carbon neutrality. 24 The working principles and process flow of the CCU technology are illustrated in Figure 2.…”

A System for the Combined Carbon Capture and Utilization to Produce Renewable Methanol from Biogas

“…The last case is identical to the latter, but the methanol is produced in a sorption‐enhanced reactor. In the energy storage cases, the electrolyzer is modeled with an efficiency model, considering a high heating value (HHV)‐based efficiency to H 2 of 70 % [14]. The capital cost of the electrolyzer is 1000 € kW −1 installed.…”

“…CO 2 is a waste stream of biogas upgrading and is normally available at high concentration. Thanks to these favorable conditions, most of the significant applications of power-to-gas reported so far are connected to biogas as CO 2 source [10][11][12][13][14].…”

Carbon Capture and Utilization Technology Development Opportunities Based on Biomethanation

“…To facilitate their growth and activity, the strains require suitable temperature and pressure conditions, as well as necessary nutrients. These nutrients are typically provided as a solution to the reactor where the methanation takes place [46]. These microorganisms belong to a highly diverse group of archaea known as methanogens.…”